Using a case epidemiologic design we will examine the natural history of women who are exposed and possibly infected by male contacts with C. trachomatis or N. gonorrhoeae and define the course of early disease in the infected woman. In particular, we will determine the frequency of pelvic inflammatory disease (PID) as a complication of these infections. This investigation will be accomplished by identifying men who are mostly monogynous and who have one or two female partners who we identify as spread contacts of males rather than source contacts. These women will be aggressively sought and examined for the presence of the organism to which they were exposed and also evaluated for complications of chlamydia or gonococcal infection, particularly pelvic inflammatory disease. These studies will identify the risk of acquiring infection after exposure to an infected regular sexual partner. These studies will also determine the frequency of development of pelvic inflammatory disease in the women after will defined, early infection. As a part of other studies (projects 3 and 4) immunologic factors that might be present in exposed but not infected women will also be examined.